Work on diachronic syntax has developed remarkably over recent decades, primarily through two impetuses: (i) seeking to explain change in I-language through changes in E-language and principles of language acquisition, and (ii) using search mechanisms linked to computerized corpora of partially parsed historical texts. The workshop will be devoted to exploring these developments. Both developments link work on sociolinguistic variation with the emergence of new I-languages and this will be an emphasis of the workshop.